Orthopaedics

Question 1

What are the 4 key considerations when deciding on the best option to repair a fracture?

Answer 1

1. Is the fracture anatomically reconstructable?
2. Where is the fracture?
3. Whar are the fracture biomechanics?
4. What is the fracture biology?

Question 2

How to determine if it is anatomically reconstructable?

Answer 2

If 2 (or 3) pieces = anatomically reconstructable.

• with biomechanical benefit
• without causing major soft tissue dame = slowing healing.

Question 3

Is this fracture anatomically reconstruble?

Answer 3

Yes, 2 piece f#

Question 4

Is this fracture anatomically reconstructable?

Answer 4

Yes, 2 piece fracture.

Question 5

Is this fracture anatomically reconstructable?

Answer 5

No, 4 piece fracture.

Question 6

Name the benefit of anatomic reconstruction.

Answer 6

It acheives load-sharing between the bone and the implant.

Question 7

Are load-sharing and antomic reconstruction possible in a comminuted fracture?

Answer 7

No.

Question 8

What is the key decision you need to make it terms of fracture repair?

Answer 8

Is is anatomically reconstructable?

Determine fracture repair options.

Determine the method of fracture reduction.

Question 9

What is the price of anatomic reconstruction?

Answer 9

Fractured bones ONLY receive blood via muscle attachments (tendons) (ie extrea osseous blood supply) until the intermedullary artery reforms.

Question 10

Why is anatomic reconstruction only possible with 2 or 3 fracture pieces?

Answer 10

1. To achieve load-sharing without causing excessive bilogical damage is realistically only acheivable with this number of fractured pieces.
2. Greater muscle damage is done in the repair of fractures with greater than 3 pieces, decreasing blood supply to the bone and hence healing time, which can lead to non-union of the fracture +/- implant failure.

Question 11

How long does it take for the medullay artery to reform?

Answer 11

Several weeks, provided the bone is healing.

Question 12

How should comminuted fractures > 3 pieces, be repaired?

Answer 12

Not be anatomically reconstructed.

Very strong method of f# fixation applied that bridges the gap. ie bridging fixation.

Types of bridging fixation:

• Bone plates
• External skeletal fixators
• Interlocking nails
  *

Question 13

What are the biological advantages of bridging the fracture?

Answer 13

By briding the gap with an implant it avoids or minimises touching the small comminuted pieces, which preserves muscle attachments. This means bone healing is quicker due to preserving blood supply to the bone.

BUT the briding fixation MUST be STRONG enough to take all the load of weight-bearing while the fracture heals.

Question 14

What are the 3 types of elbow disease?

Answer 14

Fragmented Coronoid Process (FCP)

Osteochrondrotis Dissecans (OCD)

Ununited Anconeal Process (UAP)

Question 15

Where should you palpate for elbow effusion?

Answer 15

Between the lateral epicondyle and olecranon.

In a normal patient this will be concave.

Question 16

What is the PRICE of anatomic reconstruction?

Answer 16

The bones rely soley on extrasseous periosteal blood

supply via muscle attachments until the medullary artery reforms.

Question 17

Name 4 physical Examination findings that are typical of elbow disease.

Answer 17

1. Pain on flexion

2. +/- joint effusion

3. Decreased range of motion

(crepitis / periarticular fibrosis if DJD present)

4. Muscle wasting

Question 18

What disease is shown in this radiograph?

What is the view?

Answer 18

Flexed, lateral elbow.

Ununited Anconeal Process.

The Anconceal Process arises as a secondary centre of ossification at 11-12 weeks of age and should fuse to the ulna at 4 to 5 months of age.

Question 19

What is the treatment for Ununited Anconeal Process?

Answer 19

Conservative treatment of nothing as poor outcomes as the anconeal process is unstable.

Dynamic ulna osteotomy

OR

Primary repair of the UAP with lag screw +/- ulna osteotomy.

Question 20

What is the prognosis of UAP?

Answer 20

1. Progressive DJD is inevitable whichever treatment method is used.

• Early intervention and tx significantly reduces rate of Osteoarthritis.

2. Ongoing DJD management is necessary (advice owners).

3. Breeding implications for OCD and FCP (advice owners).

Question 21

What is Osteochondrosis?

Answer 21

A disease that affects the normal endochrondral ossification of growth plates.

(Endochrondral: situated or occuring within cartilage)

Question 22

Define Osteochrondritis Dissecans

Answer 22

OCD

Question 23

You’re examining a sedated dog. The patella is out of position, you can put it back into position, as soon as you take your gingers off it, it pops out.

Answer 23

Grade III Patella Luxation

Question 24

Name 4 options for Anatomically Reconstructable long bone fractures (2 or 3 pieces)?

Answer 24

1. Casts
2. Intramedullary and cerclage wire
3. Bone Plate applied as a neutralisation plate (long and oblique spiral f#)
4. Bone plate applied as a compression plate (simple transverse f#)

Question 25

List 5 biomechanical factors that affect the stability achieved in fracture fixation.

Answer 25

1. type of fracture
2. can it be anatomically reconstructed
3. method of repair
4. is it single or mulitple limbs
5. Patient size and level of activity during the healing period